Originally Posted by Nicholson58
Our 450 AH firefly 24 volt system is solar charged daily but seldom to full. I run the generator once or twice weekly, 60 amps, 28 volts. We have completed two seven month seasons in the Caribbean on anchor with the FF. I also have a similar sized Lifeline bank in reserve that is 12 years old, still good.
Have you actually capacity checked the Lifeline bank?
I’m keeping 440 AH of Lifeline as a secondary bank too, partially as if I lose one of the Fireflies, I lose the whole bank, but also they are still good, just lost
Interestingly they have lost
capacity when I sit in a marina on 13.3 V float 24/7, not when we are cruising and cycling them, equalizing hasn’t recovered any significant capacity.
I have not done an actual correct cap check, I go by the Smart Gauge, which also tracks exactly with Lifelines
voltage under load SOC chart.
Except for the loss in capacity, my Lifeline bank is fine, it still fully charges in the same time it always has, and gets me through the night easily. If I wasn’t tracking capacity, I don’t think I would have noticed a capacity loss.
The other way I track capacity is that I have to set my amp counting battery
monitors to a lower capacity for them to match the SOC the smart gauge computes, I trust the Smart Gauge because it matches Lifelines
Point is I think many, many cruisers have banks that are “dead” but they are large enough so that even meeting the definition of dead, they still get by.
I’d bet your Lifelines at 12 yrs old are “dead” but still had enough capacity for you so they are fine.
On edit, I notice that you have no air gap between individual batteries
, do they get warm with no air circulation? Firefly specs 1” space all around each battery